You need to save it to an old DWG format, like AutoCAD 2000 or something. My understanding as far as Illustrator is concerned is that it's just not compatible with DWG files produced by more recent applications. If you have a recent version of AutoCAD, use a Save As to save it as an older version.

Hope it helps.

P.S: If this works or you do indeed find a solution take the time to let us know.

You need to save it to an old DWG format, like AutoCAD 2000 or something. My understanding as far as Illustrator is concerned is that it's just not compatible with DWG files produced by more recent applications. If you have a recent version of AutoCAD, use a Save As to save it as an older version.

Hope it helps.

P.S: If this works or you do indeed find a solution take the time to let us know.